1. Field of the Invention
This invention relates to a power window replacement module for the rear cab window of a truck.
2. Description of the Prior Art
In typical truck cabs, as provided by the manufacturer, the rear window of the truck cab cannot be opened. It is a solid piece of glass that has been glazed into the truck cab and held in place by interior and exterior window gaskets.
Consumers have found it highly desirable to be able to open the rear window of the truck cab. For example, opening the rear window improves air circulation. Some automobile accessory manufacturers have attempted to meet this demand by providing substitute windows which are split, horizontally moving windows. The original glass provided by the manufacturer is removed and the substitute, split window is inserted in its place. In these substitute windows, one-half of the window is adapted to slide past the other half in a horizontal direction. Although such windows do improve air circulation, at best, only one-half of the window may be opened to permit the flow of air into the cab.
Furthermore, such substitute window units have a further disadvantage when used with camper shells mounted on the pickup truck. Typically, such campers have a window that is positioned immediately behind the cab window of the pickup truck. If a substitute split window is used, access between the cab and the camper via the adjoining windows is limited because only one half of the window opening is available. Alternatively, the entire original window may be removed and a tube made of cloth or rubber or similar substances may be used for providing access between the cab and the camper. However, the camper body is frequently removed from the truck at a later date; thus, a piece of glass such as provided by the original manufacturer needs to be remounted in the window opening. Such replacement of the cab window is not readily done by the owner of the truck and is expensive.
It would thus be highly desirable to have a rear window unit that is fully retractable into the truck cab. Such a window unit is disclosed in U.S. Pat. No. 4,119,341 to Cook.
However, prior art embodiments have certain shortcomings. Given the substantial weight of the glass window, the gear and lever arm system used for raising and lowering the window between the fully closed and fully opened positions requires a large amount of torque. Therefore, the motor that is used for providing the mechanical power to raise and lower the window has to be quite powerful. Such motors are expensive and also are relatively noisy.
Furthermore, prior art units may not easily be installed by the typical consumer. In particular, these prior art window units require that various components of the assembly be welded onto the cab body. The typical consumer does not have ready access to welding equipment. Furthermore, the prior art enclosures require a substantial amount of space.
Thus, it is a first object of this invention to provide a power window assembly which is thin and compact, having a window that may be fully raised and lowered in place. A second object of this invention is to provide a construction that is easily mountable in a truck cab without special tools such as welding equipment. It is a further object of this invention to provide a unit that does not require as much torque out of the motor to raise and lower the window. It is yet another object of this invention to provide such devices with adequate sealing from weather and with full and free access between the truck body and a camper mounted behind the cab.